Column: GDP is a useful measurement, but it doesn’t show the whole picture

Putting too much emphasis on GDP can distort our perceptions of the strengths and weaknesses of an economy, writes Making Sen$e columnist Vikram Mansharamani. Photo by Spencer Platt/Getty Images.

Many business executives live by the creed of “What gets measured gets managed.” The metrics we use channel our attention and efforts. And when it comes to global economics, no indicator monopolizes our attention more than gross domestic product. While the measure is useful, it also has some serious shortcomings. Putting too much emphasis on GDP can distort our perceptions of the strengths and weaknesses of an economy.

GDP measures economic activity: In general, the value of final goods and services a country produces in a year. It provides a good picture of the size of the income pie. But focusing on headline GDP growth each quarter leads us to ignore important factors not captured by income statistics.

The size of the pie says nothing about how income is distributed.

For instance, the size of the pie says nothing about how income is distributed. And considering distribution, like overall income growth, is crucial for assessing an economy’s health. This is especially true since incremental dollars are not valued the same by each person; $100 is worth more to a poor person than to a wealthy one.

Imagine two countries with the same national income. In the first, 40 percent of the country’s income goes to the top 10 percent. In the second, 20 percent does. The latter country has much more income to go around to the vast majority of its citizens, and the aggregate well-being is likely to be higher.

As Simon Kuznets, the architect of GDP, put it in 1934, “economic welfare can scarcely be adequately measured unless the personal distribution of income is known.” A broader metric like the Genuine Progress Indicator adjusts personal consumption for income inequality to fill out the picture.

Headline growth figures also exclude demographic considerations. If a country’s income is growing, but not as fast as its population, then living standards can actually decline. Nigeria’s population, for instance, is growing by 2.6 percent per year, meaning that its economy needs to expand at that same rate just to maintain per capita income levels.

Even if we made sure to qualify our headline growth figures with distribution and demographics, the discussion would still be limited to income. But there are many other factors worth highlighting to evaluate how we’re doing. Take wealth, for example, which GDP figures tell us nothing about.

As the architect of GDP said, “economic welfare can scarcely be adequately measured unless the personal distribution of income is known.”

Consider two people with equal salaries, but one has $1 million in the bank and is adding to it, while the other has $6,000 in the bank and is spending more than he or she earns. Nations, too, can overspend from savings, but GDP tells us nothing about the size of the stock they have to draw from — it merely measures the income flow. High or fast-growing GDP figures might result from overconsumption, for instance, but this would not bode well for the long-run economic health of a country.

Moreover, in narrowly focusing on income, our national accounts leave out the value of leisure. This can distort our conception of the relative flourishing of countries. For instance, while the United States’ GDP per capita is roughly 15 percent higher than the Netherlands,’ American workers work 26 percent more hours than their Dutch counterparts. Which country is better off?

Some measures of national well-being incorporate the value of time explicitly. The OECD’s Better Life Index, for example, includes a work-life balance dimension. Unsurprisingly, the United States ranks near the bottom on this metric, while the Netherlands tops the list.

Another issue is GDP does not directly measure subjective well-being, and economists disagree about whether it is a decent proxy. According to the United Nations’ World Happiness Report, which focuses explicitly on gauging people’s happiness, GDP per capita only explains around a quarter of the difference in subjective happiness levels between the top 10 countries and bottom 10 countries. Other factors include healthy life expectancy, personal freedom and social support networks.

These are just a few of the blind spots that an overly narrow focus on GDP figures can produce. As Robert F. Kennedy famously said, gross national product — GDP’s close cousin — “does not allow for the health of our children, the quality of their education or the joy of their play. It does not include the beauty of our poetry or the strength of our marriages, the intelligence of our public debate or the integrity of our public officials. It measures neither our wit nor our courage, neither our wisdom nor our learning, neither our compassion nor our devotion to our country, it measures everything in short, except that which makes life worthwhile.”

Employing a diverse array of metrics gives us a better picture of how we’re doing and what we should focus on improving.

This doesn’t mean GDP, or GNP for that matter, is useless. Far from it. But analyzing the contours of GDP does force us to zoom out and understand its limitations. Relying on a single measure as a gauge of a country’s development can force us to overlook dimensions that matter.

By contrast, employing a diverse array of metrics gives us a better picture of how we’re doing and what we should focus on improving. Using a “dashboard” of indicators, as economist Diane Coyle describes in “GDP: A Brief but Affectionate History,” would help us break free from the tyranny of tunnel vision. As Coyle highlights, the OECD’s Better Life Index offers a broad set of measures and even allows users to weight them as they see fit.

I spent an hour or so fiddling with the site myself. The mere act of considering the relative importance of civic engagement and community led me to see the world differently. I encourage you to give it a try as well — it just might let you connect the dots in a way a single metric never could.

Vikram Mansharamani is a lecturer at the Harvard John A. Paulson School of Engineering and Applied Sciences. He is also the author of “Boombustology: Spotting Financial Bubbles Before They Burst” and is a regular commentator in the financial and business media.

PBS NewsHour allows open commenting for all registered users, and encourages discussion amongst you, our audience. However, if a commenter violates our terms of use or abuses the commenting forum, their comment may go into moderation or be removed entirely. We reserve the right to remove posts that do not follow these basic guidelines: comments must be relevant to the topic of the post; may not include profanity, personal attacks or hate speech; may not promote a business or raise money; may not be spam. Anything you post should be your own work. The PBS NewsHour reserves the right to read on the air and/or publish on its website or in any medium now known or unknown the comments or emails that we receive. By submitting comments, you agree to the PBS Terms of Use and Privacy Policy, which include more details.